Homomorphically Encrypted Data in Email Headers

2. The method of claim 1, wherein the second electronic communication system is the same as the first electronic communication system.

3. The method of claim 1, wherein the second electronic communication system is an electronic communication system other than the first electronic communication system.

4. The method of claim 1, wherein the encrypted encoded data is in an In-Reply-To field.

5. The method of claim 1, wherein the encrypted encoded data is in a Message-ID field.

7. The method of claim 1, wherein the encrypted encoded data includes archive data allowing an electronic communication system to perform email archive operations without accessing a local system.

8. The method of claim 1, wherein the encrypted encoded data comprises one or more of: receipt metadata, receipt decisions, receipt entities, or receipt hashes.

9. The method of claim 1, wherein the encrypted encoded data is unwritten upon leaving the first electronic communication system.

10. The method of claim 1, wherein the encrypted encoded data is blocked from entering the second electronic communication system.

11. The method of claim 1, wherein the encrypted encoded data is related to one or more of: compliance, training, internal routing, or email tracking.

12. The method of claim 1, wherein the encrypted encoded data indicates a message's trust level.

13. The method of claim 1, wherein the first email message is an active message.

15. The system of claim 14, wherein the action to be carried out comprises executing, in a stateless manner, a command that is identified uniquely by one or more of: the encoded data and a context in which the action is to be carried out.

16. The system of claim 14, wherein the action to be carried out comprises altering a characteristic of the second email based on the encoded data.

17. The system of claim 14, wherein the action to be carried out comprises sending a third email based on the encoded data.

18. The system of claim 14, wherein the message header further comprises security features associating the data with a user.

19. The system of claim 14, wherein the electronic communication system comprises an email client or an email server.

20. The system of claim 14, wherein at least one of the first encoded data or second encoded data includes information that encodes one or more portions of the email message, one or more portions including at least one portion of a subject header field of the email message, or at least one portion of a body of the email message.

21. The system of claim 20, wherein the encoded data comprises a result of a hash function applied to the one or more portions.

22. The system of claim 14, wherein the encoded data comprises one or more of: receipt metadata, receipt decisions, receipt entities, or receipt hashes.

23. The system of claim 14, wherein the encoded data is unwritten upon leaving the first electronic communication system.

24. The system of claim 14, wherein the encoded data is blocked from entering the second electronic communication system.

25. The system of claim 14, wherein the encoded data is related to one or more of: compliance, training, internal routing, or email tracking.

26. The system of claim 14, wherein the encoded data indicates a message's trust level.

27. The system of claim 14, wherein the first email message is an active message.